PC cord question for old Minolta Auto 28 flash

I've got a 7D, and an old Minolta Auto 28 flash has come into my possession. It'll happily fire using the test button on the back (i.e. it still works), but the hotshoe is obviously physically incompatible.

A little searching tells me that old flashes with high trigger voltages (I measured this one at 200V) shouldn't be attached to the hotshoe anyway, but that the PC connection would be oK.

The jack connector on the flash looks to be a 2.5mm socket, so is this (http://www.ebay.co.uk …%26ps%3D54#ht_4​142wt_1159) what I'm after? The hole appears to only be about 1/4" (6mm) deep, which seems a little too short for sub-mini jack connectors I've seen.

It's possibly a dumb question either way, but I have zero experience with PC cords/external flashes.

sploo wrote in post #13970329
, but the hotshoe is obviously physically incompatible.

What is physically incompatible? Your 7D is safe up to 250 volts. You can use it right on your hotshoe.

Use Manual mode on the 7D, set the shutter speed to 1/125 and the aperture to match what the back of the flash says.
(set the ring on the back to match your ISO, and it will tell you what aperture to use in Auto Flash.)
( I would suggest using ISO 400 or 800, and bounce the light off the ceiling)

Thanks for the info. I'd assumed (from reading various webpages) that the modern hotshoes were 6V max, but you could get away with higher using the PC connector on some bodies. The 7D manual states 250V on the PC connector, but I didn't realise it's the same voltage for the hotshoe as the PC connection (makes sense I guess). This is confirmed here: http://digitaljournali​st.org/issue0703/tech-tips.html

By physically incompatible I meant that the Minolta flash has a very different set of pins than a Canon flash. I don't have it in front of me right now, but I'm having a sneaking suspicion you might mean that the central contact is the 'firing' pin and the others around it (on a Canon hotshoe) are for data connections with a modern flash. Therefore the old flash would physically fit, and could be fired on the hotshoe - though obviously you won't get any other features. Am I getting the right end of the stick? (I am a flash noob :confused

EDIT: Checked the 7D manual, which states:

* Do not connect to the camera’s PC terminal any flash unit requiring 250 V or more.
* Do not attach a high-voltage flash unit on the camera’s hot shoe. It might not fire.

So... that doesn't really answer the question as to whether you can attach a flash requiring 200V onto the hotshoe

There is a thread here somewhere that quotes Chuck Westfall, the USA Canon rep, stating that there is only one flash trigger circuit in the cameras. There is not a separate one for the PC port and one for the shoe. So if it is 250 for one port it is 250 for both.
You might be able to do a search and find the exact quote.

dedsen wrote in post #13975555
There is a thread here somewhere that quotes Chuck Westfall, the USA Canon rep, stating that there is only one flash trigger circuit in the cameras. There is not a separate one for the PC port and one for the shoe. So if it is 250 for one port it is 250 for both.
You might be able to do a search and find the exact quote.

Yep, a quote is in the digitaljournalist link I posted above (though it might be a different specific quote from one on this forum).

I'm leaning towards it being OK. The manual states that high voltage flashes may not work, rather than "may damage the camera", but I'd like to be sure just in case.

So you have seen that a Canon rep stated that it is ok, but you want reassurance from some anonymous person on the Internet?

dedsen wrote in post #13975767
So you have seen that a Canon rep stated that it is ok, but you want reassurance from some anonymous person on the Internet?

Chuck's comments were from 2007, with an "anticipate" that future models would be 250V. The manual states "Do not attach a high-voltage flash unit on the camera’s hot shoe. It might not fire".

If someone has used the Minolta Auto 28 (or a similar voltage level flash) on a 7D regularly with no problems, that would be better reassurance for me than a 5 year old comment.

I may be being overly cautious, but I don't really fancy creating a 7D shaped paperweight for the want of doing a quick check (I've mailed Canon).

I have a minolta flash that works ok with canon body. I modified the flash so now I can attach pc cable to it. I use wireless trigger as I dont like cords

sploo wrote in post #13975692
Yep, a quote is in the digitaljournalist link I posted above (though it might be a different specific quote from one on this forum).

I'm leaning towards it being OK. The manual states that high voltage flashes may not work, rather than "may damage the camera", but I'd like to be sure just in case.

Every human has there own level of comfort on questions that are not answered directly in an absolutely definitive manner, but by integrating numerous bits of info into a reasonable explanation.

This forum is likely the #1 place on the web for Canon specific flash information.

I challenge you to find a first hand report of a damaged Canon DSLR (testimonials of knowing someone that once heard of a damage report would not count), released after the 10D or first digital rebel (300D), by a flash with a sync Voltage at or below 250 Volts.

This is an issue I have personally followed closely for about 5 years. I have personally never seen even one report (as detailed above).

If the reports are not here, where are they?

But, does this remove all doubt? This require an individual answer.

Enjoy! Lon

sploo wrote in post #13975386
EDIT: Checked the 7D manual, which states:

* Do not connect to the camera’s PC terminal any flash unit requiring 250 V or more.
* Do not attach a high-voltage flash unit on the camera’s hot shoe. It might not fire.

So... that doesn't really answer the question as to whether you can attach a flash requiring 200V onto the hotshoe

From Chuck Westfalls testimonial:

"The trigger circuit voltage (TCV) rating for any EOS SLR is the same on the hot shoe as it is on the PC terminal (if the camera has one)"

See:

http://digitaljournali​st.org/issue0703/tech-tips.html

Now whither this is sufficient for your acceptance is another issue.

Enjoy! Lon

Thanks for the replies.

Lon - yea, the Chuck Westfall comment from digitaljournalist was the one I'd linked further up. It was the wording in the 7D manual that's just given me a little caution.

As expected, the Minolta flash fits on the hotshoe OK, and a quick bit of research indicates its single pin is the central 'X' sync, so in terms of being able to be fired by the camera it looks physically compatible (I understand some of the SONY/Minolta flashes have a non-standard layout, but this one pre-dates that configuration).

Given Chuck's comments (and the fact the 7D's PC connection is safe for 250V), I'd be very surprised if the 7Ds hotshoe wasn't OK for this flash. But, I don't need to use it immediately, so I'm happy to wait for an answer from Canon. I do however need the camera in the next couple of days, so I'd feel very dumb to have killed it with a noob mistake for the want to trying something I didn't need immediately.

sploo wrote in post #13981931
so I'm happy to wait for an answer from Canon.

It is extremely unlikely you will get a direct and thoughtful reply from Canon on this issue.

Again, I have followed this issue for 5 years and every reply I have seen from Canon was either:

1) From a very low level technician that really did not understand the issue and provided an answer that was obviously incorrect or incomplete (and no one had any confidence in).

or

2) From a higher level technician that sidestepped the issue on purpose.

If you are expecting something more definite that Chuck Westfalls' testimonial (already highlighted) you will likely be left wanting.

Enjoy! Lon

FlashZebra wrote in post #13986055
It is extremely unlikely you will get a direct and thoughtful reply from Canon on this issue...

I fully suspect you're right. Short of taking a 7D to pieces and tracing all the electronics. Hang on that gives me an idea...

...just checked with a multimeter, and (perhaps unsurprisingly) the ground planes are the same. The firing contact could be connected to a different circuit, but you'd suspect it was also the same (that's not something I could check without ripping it apart).

Will give them a little time to respond. No answer means I'll probably risk it at some point.

Well, Canon called today... while I was out ... and left a message to tell me that hotshoe on the 7D is safe only up to 6V. Which directly contradicts Westfall's info.

Given this isn't about an opinion; it's about what the circuitry in the camera is designed to do, one wonders why a tech company can't just state clearly in the manual the specification of part of its product .

More info indicating it's probably safe:
http://dpanswers.com …rc_flash_measur​etv.php#tv
http://photo.stackexch​ange.com …d-flash-damage-a-new-dslr

Having confirmed the ground on the hotshoe and PC connector are the same (audible signal using a multimeter) I tried another test tonight - using one probe on the hotshoe center pin and another on the hotshoe ground results in an audible 'pip' from the meter when you fire an exposure (to set off an external flash) - as expected.

However, when doing the same with the PC socket, I get no signal. Is there some setting that needs to be done to make the PC connector work?

sploo wrote in post #14001089
Well, Canon called today... while I was out ... and left a message to tell me that hotshoe on the 7D is safe only up to 6V. Which directly contradicts Westfall's info.

Given this isn't about an opinion; it's about what the circuitry in the camera is designed to do, one wonders why a tech company can't just state clearly in the manual the specification of part of its product .

More info indicating it's probably safe:
http://dpanswers.com …rc_flash_measur​etv.php#tv
http://photo.stackexch​ange.com …d-flash-damage-a-new-dslr

Having confirmed the ground on the hotshoe and PC connector are the same (audible signal using a multimeter) I tried another test tonight - using one probe on the hotshoe center pin and another on the hotshoe ground results in an audible 'pip' from the meter when you fire an exposure (to set off an external flash) - as expected.

However, when doing the same with the PC socket, I get no signal. Is there some setting that needs to be done to make the PC connector work?

From my post above:

"It is extremely unlikely you will get a direct and thoughtful reply from Canon on this issue.

Again, I have followed this issue for 5 years and every reply I have seen from Canon was either:

1) From a very low level technician that really did not understand the issue and provided an answer that was obviously incorrect or incomplete (and no one had any confidence in).

or

2) From a higher level technician that sidestepped the issue on purpose.

If you are expecting something more definite that Chuck Westfalls' testimonial (already highlighted) you will likely be left wanting."

And from my earlier post regarding the 6 Volt limit on the hotshoe:

"This forum is likely the #1 place on the web for Canon specific flash information.

I challenge you to find a first hand report of a damaged Canon DSLR (testimonials of knowing someone that once heard of a damage report would not count), released after the 10D or first digital rebel (300D), by a flash with a sync Voltage at or below 250 Volts.

This is an issue I have personally followed closely for about 5 years. I have personally never seen even one report (as detailed above).

If the reports are not here, where are they?"

There are hundreds of models of common flash units that have a sync Voltage in excess of 6 Volts. If it only takes 6 Volts for damage, where are the scores of reports of damaged Canon DSLRs (released after the 10D and 300D)? Some of these flash units with sync Voltage above 6 Volts had to end up on the millions of Canon DSLRs released after the 10D ad 300D.

Enjoy! Lon